Wanaka police are cautioning people to be careful with their cooking equipment outdoors after a large blaze burnt through a Department of Conservation (Doc) reserve at Glendhu Bluffs on Sunday and Monday.

An investigation by Fire and Emergency NZ (Fenz) is not complete but Senior Constable Bruce McLean wrote in Wanaka’s Crimeline on Tuesday that police knew what the cause was.

“We know the cause of the fire. Make sure you are careful cooking and use no naked flames or smoking in the outdoors where the ground is tinder dry. A fire doesn’t take much to start and gets out of control very quickly,” Snr Const McLean said.

The 280-hectare fire is understood to have started between Wanaka-Mt Aspiring Rd and Emerald Bay on Sunday afternoon. It was reported about 1.30pm.

Fenz incident controller Jason Sarich said it could take at least a week to complete the investigation.

A fire investigator has visited the site.

Mr Sarich cautioned people to check conditions before they undertook outdoor activities.

He confirmed on Tuesday the fire had not spread overnight on Monday and had been contained.

Four crews of firefighters focused on dampening down hot spots identified by thermal imaging early on Tuesday.

The hot spots were all within the 7.1km perimeter of the containment area.

Tuesday’s crews were from Glenorchy, Dunstan and Doc .

They wanted to address the hot spots ahead of the hottest part of the day, when fires could flare up.

Weather conditions during the fire were windy with high temperatures and low humidity.

This was challenging from a firefighting perspective so crews were on alert to ensure the fire remained contained.

At the peak of the blaze, eight fire crews and nine helicopters with monsoon buckets were at the scene.

Seven power poles were burned down, affecting 78 Aurora Energy customers, the majority of whom had power restored by Sunday night.

Aurora Energy crews were waiting for Fenz clearance on Tuesday so they could begin replacing the poles and reconnecting about 35 remote customers. This would take several days.

In the meantime, Aurora was arranging for generators to be delivered to those affected.

Access past the fire zone on Wanaka-Mt Aspiring Rd will be controlled this week.

There are concerns the fire could flare up during an ongoing period of hot, dry weather.

Glendhu Station farmer John McRae said parts of his farm were burned, as well as parts of the Parkins Bay Golf Course project.

“I think of what happened at Lake Ohau or in Australia. Our firefighters deserve a good shout-out,” Mr McRae said.